The present invention relates generally to disk drives for storing data. More specifically, the present invention relates to a fluid diffuser for a disk drive.
Disk drives are widely used in computers and data processing systems for storing information in digital form. These disk drives commonly use one or more rotating storage disks to store data. Each storage disk typically includes a data storage surface on each side of the storage disk. These storage surfaces are divided into a plurality of narrow, annular regions of different radii, commonly referred to as xe2x80x9ctracksxe2x80x9d. Typically, a positioner is used to move an E-block and a transducer assembly having a data transducer over each data storage surface of the storage disk. The data transducer transfers information to and from the storage disk when positioned over a target track of the storage surface.
The need for increased storage capacity and compact construction of the disk drive has led to the use of storage disks having increased track density or decreased track pitch, i.e., more tracks per inch. As the tracks per inch increase, the ability to maintain the data transducer over the target track becomes more difficult. For example, disk drives in use today can require that the data transducer remain on the target track to within less than 1 millionth of an inch. Stated another way, as track density increases, it is necessary to reduce the positioning error of the data transducer proportionally. With these systems, the accurate and stable positioning of the data transducer is critical to the accurate transfer of data between the data transducer and the storage disk.
Moreover, the need for decreasing data transfer times has led to ever-increasing rotational velocities of the storage disks. However, as the storage disks rotate, air or other fluids in the spaces between adjacent storage disks is dragged along with the rotating disks and is accelerated outwardly and/or linearly toward the perimeter of the storage disks by centrifugal and/or centripetal forces. The accelerated fluid is propelled from the spaces between the storage disks, resulting in low-pressure regions between adjacent storage disks. Fluid rushes in at a relatively high velocity because of the pressure differential to fill the low-pressure regions. This repeated cycle causes chaotic and random flutter of the storage disks and high-velocity fluid flow between the storage disks. This high-energy fluid flow can cause the E-block and the transducer assemblies to vibrate and become excited. The vibration makes it more difficult to position and maintain the data transducer over the target track. The fluid flow becomes even more disruptive as the storage disks rotate more rapidly and are positioned increasingly closer together. The inability to maintain the data transducer over the target track is also referred to herein as track misregistration. Thus, the ability to avoid track misregistration is becoming more difficult.
Attempts to reduce track misregistration caused by high-energy fluid flow include positioning an air dam at various locations in the drive housing. A typical air dam attempts to block the majority of the flow of fluid to the E-block and the transducer assemblies. Unfortunately, existing air dams can create differential pressure regions that result in increased high-energy fluid flow near the transducer assemblies and the E-block.
In light of the above, the need exists to provide a reliable, simple, and efficient device that effectively decreases the velocity of fluid flow near the transducer assemblies. Another need exists to provide a disk drive with a reduced incidence of track misregistration that is relatively easy and cost effective to manufacture.
The present invention is directed to a disk drive that includes a drive housing, a rotating first storage disk having a first storage surface, and a fluid diffuser. The rotating storage disk generates fluid flow within the drive housing. The fluid diffuser includes a first diffuser wing that is substantially stationary relative to the drive housing. The first diffuser wing has a first wing surface positioned near the first storage surface. The first diffuser wing includes one or more spaced-apart surface deviations that disrupt the fluid flow over the first wing surface. In one embodiment, the surface deviation is an indentation into the first wing surface of the first diffuser wing. In another embodiment, the surface deviation extends away from the first wing surface towards the first storage surface. In still another embodiment, the surface deviation is an aperture that extends through the first diffuser wing. Alternately, the first diffuser wing can include a combination of these surface deviations.
The disk drive can also include a rotating second storage disk. The first diffuser wing can be positioned substantially between the first storage disk and the second storage disk. Moreover, the fluid diffuser can include a plurality of diffuser wings that can be positioned substantially between the first storage disk and the second storage disk. The diffuser wings can divert the fluid flow substantially toward or away from the storage surfaces of the storage disks.
The present invention is also directed to a disk drive that includes a pair of spaced apart, rotating storage disks that each has a storage surface, and a fluid diffuser. In this embodiment, the diffuser wing has a wing surface, and is positioned between the storage surfaces of the storage disks. The diffuser wing includes a surface deviation that extends from the wing surface toward one of the storage surfaces. The wing surface can be substantially planar or can be curved. Further, a portion of the surface deviation can form an angle with the wing surface that is greater than approximately 0 degrees and less than approximately 180 degrees.
The present invention also includes a method for enhancing the accuracy and/or the reliability of a disk drive.